<ul class="title">
    <li v-for="(_i,index) in title_arr" :key="index">
        <i :class="{on:index == current_index}"></i>
        <span>{{_i.title}}</span>
    </li>
</ul>
<ul class="content">
    <li v-for="(_i,index) in content_arr" :key="index">
        <img :src="_i.contentUrl" :alt="_i.title">
        <span class="content-title">{{_i.title}}</span>
        <span class="detail">{{_i.detail}}</span>
        <span class="price">定金：￥{{_i.price}}</span>
    </li>
</ul>